Xref: utzoo comp.unix.questions:13715 comp.sys.sequent:279
Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!ndcheg!uceng!kamat
From: kamat@uceng.UC.EDU (Govind N. Kamat)
Newsgroups: comp.unix.questions,comp.sys.sequent
Subject: Re: Possible Sh bug?
Keywords: SUN4, Sequent S81
Message-ID: <1034@uceng.UC.EDU>
Date: 19 May 89 03:45:22 GMT
References: <1002@syma.sussex.ac.uk>
Followup-To: comp.unix.questions
Organization: College of Engg., Univ. of Cincinnati
Lines: 32

In article <1002@syma.sussex.ac.uk> andy@syma.sussex.ac.uk (Andy Clews) writes:

>% sh
>$ echo $?
>0
>$ if [ $? != 0 ]; then exit 1; fi
>$ echo $?
>0
>
>Why the different value of $? at the end of each example? Which system
>is at fault? Or are they both wrong :-) :-)

The Sun version is right.  The return code of an "if" is supposed to
be 0 in case none of the branches gets executed.  To avoid this
behavior of the "if", you can use

[ $? -ne 0 ] && exit 1
echo $?

which will return a 1.

>What exit status (value) should the "if" return? My understanding is
>that "exit" only works in non-interactive shells (see man sh(1)), but
>surely in the above, it shouldn't get as far as the "exit" anyway
>because $? is 0. 

Exit should work the same in both interactive and non-interactive
shells.  Perhaps your sh(1) behaves differently.
-- 
Govind N. Kamat				College of Engineering
kamat@uceng.UC.EDU			University of Cincinnati
					Cincinnati, OH 45221, USA